With the increasing use of HF surgery, and electrically driven or actuated diagnostic and therapeutic instruments, there has been a great expansion in the use of hand-held medical instruments or devices for which the handling includes the initiation of switching functions. Instruments and devices of this kind, or the associated manipulating parts, are used with electric push buttons.
There is the problem that the penetration of liquids, due to the use, cleaning, disinfection and sterilization of the products, can cause the push buttons to become damaged because the penetration of moisture causes the push button/contact to fail; as such, the function of the product is no longer guaranteed.
These types of manipulating parts are sealed at interfaces such as cable outlets, contact insertion area, push button area (via sealing rings, films, bonding, etc) such that the penetration of liquids is avoided to protect the button elements and their function. In addition, the push buttons have a splash-proof design; however, due to ambient conditions, this only provides conditional protection in the case of sterilization using moist heat.
The increased use of manipulating parts of the type described above has revealed certain problems. On the one hand, sealing all of the interfaces of the manipulating elements is a very complex constructional task and, on the other, there is a risk of leaks after repeated use. If moisture enters at one point, the other seals are functionless and moisture can penetrate the interior of the handles.